Electrically Operated Aerosol Generation System

ABSTRACT

An aerosol generation system for generation of an aerosol from an aerosol-forming precursor includes an electrically operated heating system to heat the precursor to generate the aerosol, a flow path for transmission of flow, including the aerosol, to a user, the heating system arranged in fluid communication with the flow path, and electrical circuitry. The electrical circuitry is configured to determine a feature of an oscillation associated with a property of electrical energy through the heating system, the oscillation due to initiation and/or termination of a user inhale through the flow path, and to determine an amount of one or more components of aerosol dispensed in the inhale based on the feature of the oscillation.

TECHNICAL FIELD

The present disclosure relates to the field of electrically operatedaerosol generation systems in which an aerosol is formed from anaerosol-forming precursor and delivered to a user. In particular thedisclosure relates to determining properties of flow through saidsystems, which includes the aerosol.

BACKGROUND

Aerosol generation systems comprise a storage portion for storing anaerosol-forming precursor. The precursor may comprise a liquid. Aheating system may be formed of one or more electrically activatedresistive heating elements, which are arranged to heat said precursor togenerate the aerosol. The aerosol is released into a flow path extendingbetween an inlet and outlet of the system. The outlet may be arranged asa mouthpiece, which a user inhales through for delivery of the aerosolto the user.

The system may implement measurement of the depletion of the precursorto determine the quantity of one or more components thereof delivered toa user. Measurement may also be implemented to determine the quantity ofprecursor that remains in the storage portion so that the user can benotified when replenishment is required. Such measurement may beimplemented by means of a flow meter or a level sensing systemassociated with the storage portion. It may be desirable to develop acost-effective and/or reliable means for measuring depletion.

In spite of the effort already invested in the development of aerosolgeneration systems further improvements are desirable.

SUMMARY

The present disclosure provides an aerosol generation system forgeneration of an aerosol from an aerosol-forming precursor, the systemcomprising: an electrically operated heating system to heat saidprecursor to generate the aerosol; a flow path for transmission of flow,including the aerosol, to a user; the heating system arranged in fluidcommunication with the flow path; electrical circuitry to determine acharacteristic associated with a second order time derivative of aproperty of electrical energy through the heating system, and todetermine a property related to the flow of the flow path based on thecharacteristic of the second order time derivative.

By implementing determination of the characteristic from the secondorder time derivative it has been found that the characteristic (such asan amplitude, period, rise time or time of peak or area associated withan oscillation in said property) may be most accurately located anddetermined. Consequently, the property of the flow may be mostaccurately calculated. In particular, in implementations wherein theproperty (e.g. power, current or voltage) is maintained as a constant orto maintain a constant temperature, it has been found that the secondorder time derivative converges faster to a nominal value than currentwithout numerical differentiation, whereby the characteristic can bemost easily determined.

In embodiments, the property related to the flow is one or more of: anamount of one or more components of the aerosol; a start of an inhale;an end of an inhale; a duration of an inhale. “amount” may refer to anumerical quantity (e.g. a mass) as opposed to the presence or absenceof the one or more components.

In embodiments, the characteristic comprises one or more of: anamplitude; a period; an area bounded by the maxima and/or minima of theoscillation from which an intensity, i.e. flow rate, of the inhalationcan be inferred.

In embodiments, a characteristic of said feature is directly related toan amount of the one or more components of aerosol dispensed. Bydirectly related it is meant that the greater the magnitude of thefeature the greater the amount of the component dispensed, e.g. viadirect proportionality or other mathematical function relationship.

In embodiments, the circuitry may implement control to regulate aproperty of the heating system as a constant, e.g. a temperature of theheating system is regulated to a target temperature or a voltage overthe heating system is regulated to a target voltage. Said control may beimplemented by pulse width modulation (PWM) or other appropriate meanssuch as a DC:DC converter. In embodiments, a temporal displacement ofsaid regulated property from a target magnitude may be determined as aresult of an inhalation through the flow path and cooling of the heatingsystem. The characteristic associated with a property of electricalenergy can be based at least partially on said displacement.

In embodiments, the circuitry may implement measurement of a temperatureof the heating system, e.g. by measuring an electrical resistance of theheating system and determining a temperature from said resistance basedon an empirical relationship between the resistance and temperature orby a dedicated temperature sensor.

The present disclosure provides a method of determining a property of aflow of an aerosol generation system, the method comprising: determininga characteristic associated with a second order time derivative of aproperty of electrical energy through a heating system; determining theproperty related to the flow based on the characteristic of the secondorder time derivative. The method may implement any method ofembodiments disclosed herein.

The present disclosure provides an aerosol generation system forgeneration of an aerosol from an aerosol-forming precursor, the systemcomprising: an electrically operated heating system to heat saidprecursor to generate the aerosol; a flow path for transmission of flow,including the aerosol, to a user; the heating system arranged in fluidcommunication with the flow path; electrical circuitry to determine afeature of an oscillation of a property of electrical energy through theheating system, the oscillation due to initiation and/or termination ofa user inhale through the flow path, and to determine an amount of oneor more components of aerosol dispensed in the inhale based (includingat least partially based) on the feature of the oscillation.

By at least partially basing calculation of the amount of one or morecomponents of aerosol dispensed in the inhale on a characteristic ofoscillation, which is due to initiation and/or termination of the userinhale, the characteristics during the entire inhalation may not berequired to be determined, for example, if only one of said initiationor termination oscillations can be identified.

In embodiments, the feature comprises one or more of: an amplitude; aperiod; an area bounded by the maxima and/or minima of the oscillationfrom which an intensity, i.e. flow rate, of the inhalation can beinferred.

It is to be understood that the oscillation due to initiation and/ortermination of a user inhale refers to the change or fluctuation in theproperty of the electrical energy at the respective start and end of aninhalation, and in particular not an overall oscillation that may occurfrom start to end of an inhalation. The duration of the oscillation dueto initiation and/or termination of a user inhale may for example beless than 10 or 5% of the overall duration of the inhalation. Inembodiments, this fluctuation may be particularly apparent from thesecond order time derivative.

In embodiments, a magnitude of said feature is directly related to anamount of the one or more components of aerosol dispensed. By directlyrelated it is meant that the greater the magnitude of the feature thegreater the amount of the component dispensed, e.g. via directproportionality or other mathematical function relationship.

The present disclosure provides a method of determining a feature of anoscillation of a property of electrical energy through a heating system,the oscillation due to initiation and/or termination of a user inhalethrough the flow path, determining an amount of aerosol dispensed in theinhale based on the feature of the oscillation. The method may implementany method of embodiments disclosed herein.

The present disclosure provides an aerosol generation system forgeneration of an aerosol from an aerosol-forming precursor, the systemcomprising: an electrically operated heating system to heat saidprecursor to generate the aerosol; a flow path for transmission of flow,including the aerosol, to a user; the heating system arranged in fluidcommunication with the flow path. The circuitry to: measure a propertyof the electrical energy through the heating system; determine one ormore characteristics from said measured property of the electricalenergy (e.g. during a user inhalation through the flow path, whichimparts a cooling effect on the heating system that can be determined bysaid measured property); select, based on the determinedcharacteristics, one from a plurality of different empiricalrelationships between the measured property of the electrical energy anda property of the flow; implement said relationship to determine theproperty of the flow.

By selecting a particular empirically obtained relationship, which is torelate the characteristics of the electrical energy to the property ofthe flow, based on a property of the measured electrical energy, themost appropriate relationship of several can be implemented to mostaccurately calculate said property of the flow.

In embodiments the property of the electrical energy may comprise theelectrical current or power through or the electrical potential over theheating system. All of which can be conveniently measured by thecircuitry, e.g. by various current and/or electrical potential measuringimplementations.

In embodiments the property related to the flow is an amount of one ormore components of the aerosol in the flow path, wherein the aerosol isgenerated from the precursor by an atomizer of the system. The flow mayalso comprise air sucked through the flow path by a user inhalation.

In embodiments, the characteristic is based on one or more of an:amplitude or period or area of an oscillation of said electrical energyor a time derivative thereof; an initiation time of a user inhalethrough the flow path; a duration of a user inhale through the flowpath; a duration of electrical energy applied to the heating system. Byselecting the amplitude or period or area of an oscillation of saidelectrical energy, a determination of the intensity of the inhalation,e.g. the flow rate, may be provided.

In embodiments, the empirical relationship comprises an empiricallyobtained mathematical formula. The empirical relationship may comprisean output value as the property of the flow. The output value may berelated to one or more input values, each comprising the determinedcharacteristic or another characteristic of the flow (e.g. the samecharacteristics used to select the relationship may be used as inputand/or different characteristics).

In embodiments the electrical circuitry is configured to determine ifsaid first one or more input values can be obtained from the measuredproperty of the electrical energy, and to select said relationship basedon the input values obtained. By selecting the relationship based onwhether the associated input values can all be obtained, only arelationship that can provide a representative output value may beimplemented.

In embodiments, a first relationship comprises as input a first set ofone or more input values and a second relationship comprises a differentsecond set of one or more input values, the circuitry to implement thefirst relationship if the first set of input values are obtainable elseto implement the second relationship if the second set of input valuesare obtainable. By selecting a second relationship for which the inputvalues can all be obtained instead of a first relationship for which theone or more input values cannot be obtained, a representative output canbe obtained.

In embodiments, the second set of input values form a subset of thefirst set of input values. By selecting the second set of input valuesto consist of one or more of the first set of input values (whilst beingnumerically fewer than the first set), the second set can be determinedwhen partially determining the first set, hence the second set does notrequire separate steps of computation to obtain.

In embodiments, the first set of one or more input values includesamplitude or period or an area of an oscillation of said electricalenergy or a time derivative thereof, and the second set of one or moreinput values does not include an amplitude of an oscillation or saidelectrical energy or a time derivative thereof. By selecting the firstset to include amplitude or period or an area of an oscillation, thefirst relationship can be based on intensity of the inhalation, e.g. theflow rate, and provides an accurate output value, and by not basing thesecond relationship on intensity a less accurate, but more reliablesecond relationship is provided.

In embodiments, the first and second set of input values includes aduration of a user inhale through the flow path and/or a duration ofelectrical energy applied to the heating system (e.g. a duration of anactuation of a vaping button). By selecting common input values toinclude said durations, the duration of an inhalation through the flowpath can be accounted for, as opposed to just the flow rate, whendetermining the overall quantity of aerosol delivered for an inhalation.

In embodiments, the circuitry is configured such that if a set of inputvalues is unobtainable, the output value is determined from an outputvalue determined from a prior user inhale. By determining the outputvalue from a prior inhalation in the instance that the first (or bothfirst and second) relationship cannot be implemented (e.g. due to theassociated input values not being obtainable), the system includes areliable means for determining an output value.

The present disclosure provides a method of determining a property of aflow of an aerosol generation system, the method comprising: measuring aproperty of the electrical energy through the heating system;determining one or more characteristics from said measured property ofthe electrical energy; selecting, based on the determinedcharacteristics, one from a plurality of different empiricalrelationships between the measured property of the electrical energy anda property of the flow; implementing said relationship to determine theproperty of the flow. The method may implement any method of embodimentsdisclosed herein.

The present disclosure provides an aerosol generation system forgeneration of an aerosol from an aerosol-forming precursor, the systemcomprising: an electrically operated heating system to heat saidprecursor to generate the aerosol; a flow path for transmission of flow,including the aerosol, to a user; the heating system arranged in fluidcommunication with the flow path; electrical circuitry to apply apredetermined amount of electrical energy to the heating system tostabilise a property of electrical energy through the heating system,the electrical circuitry to determine a property related to the flow ofthe flow path based on the stabilised property of the electrical energythrough the heating system, wherein the property related to the flow isone or more of: an amount of one or more components of the aerosol.

By applying a predetermined amount of electrical energy to the heatingsystem to stabilise a property of the electrical energy therethrough, aparticular feature of the property of the electrical energy (such as anamplitude, period or area of an oscillation) may be extracted withincreased accuracy and thus used to determine the property related tothe flow with corresponding increased accuracy.

The present disclosure provides a method of determining a property of aflow of an aerosol generation system, the method comprising: applying apredetermined amount of electrical energy to a heating system tostabilise a property of electrical energy through the heating system;determining the property related to the flow based on the stabilisedproperty of the electrical energy through the heating system, whereinthe property related to the flow is one or more of: an amount of one ormore components of the aerosol.

The present disclosure provides a computer program or electricalcircuitry or a computer readable medium including the computer programto implement one or more of the previously disclosed methods.

BRIEF DESCRIPTION OF THE FIGURES

Aspects, features and advantages of embodiments of the presentdisclosure will become apparent from the following description ofembodiments in reference to the appended drawings, in which likenumerals denote like elements.

FIG. 1 is a block system diagram showing embodiment componentry of anaerosol generation system.

FIG. 2 is a schematic diagram showing embodiment componentry of thesystem of FIG. 1.

FIG. 3 is a schematic diagram showing an embodiment of the system ofFIG. 1.

FIG. 4 is a flow diagram showing embodiment processes implemented by thesystem of FIG. 1 to determine a property of flow through said system.

FIG. 5 is a schematic diagram showing embodiment componentry of theaerosol generation system of FIG. 1.

FIG. 6 is a schematic diagram showing embodiment circuitry of the systemof FIG. 1, the circuitry for determining the property of the electricalenergy through a heating system.

FIG. 7 is a schematic diagram showing a more detailed implementation ofthe circuitry of FIG. 6.

FIG. 8 is a graphical diagram showing an example of electrical currentthrough an electrical heating system of the embodiment circuitry of FIG.6 or 7.

FIG. 9 is a graphical diagram showing the electrical current of FIG. 9and a second order time derivative thereof.

FIG. 10 is a graphical diagram showing an example of electrical currentand a second order time derivative thereof through an electrical heatingsystem of the embodiment circuitry of FIG. 6 or 7, with the effect of auser inhale through a flow path of the system of FIG. 1 shown in detail.

FIG. 11 is a graphical diagram showing an example of electrical currentand a second order time derivative thereof through an electrical heatingsystem of the embodiment circuitry of FIG. 6 or 7, with the effect of auser inhale through a flow path of the system of FIG. 1 shown in detail,wherein the inhalation is initiated earlier than as shown in FIG. 10.

FIG. 12 is a flow diagram showing embodiment processes implemented bythe system of FIG. 1 to determine a property of flow through saidsystem, wherein the property is stabilised by a predetermined amount ofelectrical energy prior to determination of said property.

FIG. 13 is a flow diagram showing embodiment processes implemented bythe system of FIG. 1 to determine a property of flow through saidsystem, wherein the property is based on an oscillation in a property ofthe electrical energy through a heating system thereof, the oscillationbeing due to an initiation and/or termination of an inhalation of flowthrough said system.

FIG. 14 is a flow diagram showing embodiment processes implemented bythe system of FIG. 1 to determine a property of flow through saidsystem, wherein the property is determined using one of a plurality ofdifferent relationships.

DETAILED DESCRIPTION OF EMBODIMENTS

Before describing several embodiments of an aerosol generation system,it is to be understood that the system is not limited to the details ofconstruction or process steps set forth in the following description. Itwill be apparent to those skilled in the art having the benefit of thepresent disclosure that the system is capable of other embodiments andof being practiced or being carried out in various ways.

The present disclosure may be better understood in view of the followingexplanations:

As used herein, the term “aerosol generation apparatus” or “apparatus”may include a smoking apparatus to deliver an aerosol to a user,including an aerosol for smoking, by means of an aerosol generating unit(e.g. a heater or atomiser which generates a vapour which condenses intoan aerosol before delivery to an outlet of the apparatus at, forexample, a mouthpiece, for inhalation by a user). An aerosol for smokingmay refer to an aerosol with particle sizes of 0.5-7 microns. Theparticle size may be less than 10 or 7 microns. The apparatus may beportable. “Portable” may refer to the apparatus being for use when heldby a user. The apparatus may be adapted to generate a variable amount ofaerosol, e.g. by activating an atomizer for a variable amount of time(as opposed to a metered dose of aerosol), which can be controlled by atrigger. The trigger may be user activated, such as a vaping buttonand/or inhalation sensor. The apparatus may be adapted to generate avariable amount of aerosol, e.g. by activating an atomizer for avariable amount of time (as opposed to a metered dose of aerosol), whichcan be controlled by a trigger. The trigger may be user activated, suchas a vaping button and/or inhalation sensor. The inhalation sensor maybe sensitive to the strength of inhalation as well as the duration ofinhalation so as to enable more or less vapour to be provided based onthe strength of inhalation (so as to mimic the effect of smoking aconventional combustible smoking article such as a cigarette, cigar orpipe, etc.). The apparatus may include a temperature regulation controlsuch as for example a Proportional, Integral, Differential (PID)controller to quickly drive the temperature of the heater and/or theheated aerosol generating substance (aerosol pre-cursor) to a specifiedtarget temperature and thereafter to maintain the temperature at thetarget temperature regardless of the amount of substrate (pre-cursor)available at the aerosol generating unit and regardless of the strengthwith which a user inhales.

As used herein, the term “aerosol generation system” or “system” mayinclude the apparatus and optionally other circuitry/componentryassociated with the function of the apparatus, e.g. a peripheral deviceand/or other remote computing device.

As used herein, the term “aerosol” may include a suspension of precursoras one or more of: solid particles; liquid droplets; gas. Saidsuspension may be in a gas including air. Aerosol herein may generallyrefer to/include a vapour. Aerosol may include one or more components ofthe precursor.

As used herein, the term “aerosol-forming precursor” or “precursor” or“aerosol-forming substance” or “substance” may refer to one or more ofa: liquid; solid; gel; other substance. The precursor may be processableby an atomizer of the apparatus to form an aerosol as defined herein.The precursor may comprise one or more of: nicotine; caffeine or otheractive component. The active component may be carried with a carrier,which may be a liquid. The carrier may include propylene glycol orglycerine. A flavouring may also be present. The flavouring may includeEthylvanillin (vanilla), menthol, Isoamyl acetate (banana oil) orsimilar.

As used herein, the term “electrical circuitry” or “electric circuitry”or “circuitry” or “control circuitry” may refer to, be part of, orinclude one or more of the following or other suitable hardware orsoftware components: an Application Specific Integrated Circuit (ASIC);electronic/electrical circuit (e.g. passive components, which mayinclude combinations of transistors, transformers, resistors,capacitors); a processor (shared, dedicated, or group); a memory(shared, dedicated, or group), that may execute one or more software orfirmware programs; a combinational logic circuit. The electricalcircuitry may be centralised on the apparatus or distributed, includingdistributed on board the apparatus and/or on one or more components incommunication with the apparatus, e.g. as part of the system. Thecomponent may include one or more of a: network-based computer (e.g. aremote server); cloud-based computer; peripheral device. The circuitrymay be implemented in, or functions associated with the circuitry may beimplemented by, one or more software or firmware modules. The circuitrymay include logic, at least partially operable in hardware.

As used herein, the term “processor” or “processing resource” may referto one or more units for processing including an ASIC, microcontroller,FPGA, microprocessor, digital signal processor (DSP) capability, statemachine or other suitable component. A processor may include a computerprogram, as machine readable instructions stored on a memory and/orprogrammable logic. The processor may have various arrangementscorresponding to those discussed for the circuitry, e.g. on-board and/oroff board the apparatus as part of the system.

As used herein, the term “computer readable medium/media” may includeconventional non-transient memory, for example one or more of: randomaccess memory (RAM); a CD-ROM; a hard drive; a solid state drive; aflash drive; a memory card; a DVD-ROM; a floppy disk; an optical drive.The memory may have various arrangements corresponding to thosediscussed for the circuitry/processor.

As used herein, the term “communication resources” may refer to hardwareand/or firmware for electronic information transfer. Wirelesscommunication resources may include hardware to transmit and receivesignals by radio and may include various protocol implementations e.g.the 802.11 standard described in the Institute of Electronics Engineers(IEEE) and Bluetooth™ from the Bluetooth Special Interest Group ofKirkland Wash. Wired communication resources may include UniversalSerial Bus (USB); High-Definition Multimedia Interface (HDMI) or otherprotocol implementations. The apparatus may include communicationresources for communication with a peripheral device.

As used herein, the “heating system (being) arranged in fluidcommunication with the flow path” may refer to an interaction orexchange between the heating system and the flow transmitted by the flowpath, such as (but not limited to) between components of the heatingsystem, such a heating coil, and air, precursor, solid materials and/oraerosol comprised in the flow. For example, the heating system is influid communication with the flow path if a heating element such as acoil is located in the flow path. In this case, the heating elementheats the flow, and vice versa the flow may have a cooling effect on theheating element.

As used herein, the term “network” or “computer network” may refer to asystem for electronic information transfer. The network may include oneor more networks of any type, which may include: a Public Land MobileNetwork (PLMN); a telephone network (e.g. a Public Switched TelephoneNetwork (PSTN) and/or a wireless network); a local area network (LAN); ametropolitan area network (MAN); a wide area network (WAN); an InternetProtocol Multimedia Subsystem (IMS) network; a private network; theInternet; an intranet.

As used herein, the term “peripheral device” may include electroniccomponents peripheral to an apparatus. The peripheral device maycomprise electronic computer devices including: a smartphone; a PDA; avideo game controller; a tablet; a laptop; or other like device.

As used herein, the term “storage portion” may refer to a portion of theapparatus adapted to store the precursor.

As used herein, the term “delivery system” may refer to a systemoperative to deliver, by inhalation, aerosol to a user. The deliverysystem may include a mouthpiece or an assembly comprising a mouthpiece.

As used herein, the term “flow path” may refer to a path or enclosedpassageway through the apparatus, through which the user may inhale fordelivery of the aerosol. The flow path may be arranged to receiveaerosol.

As used herein, the term “flow” may refer to a flow in the flow path,and may include air, which may be induced into the flow path due to aninhalation through the flow path and/or aerosol.

As used herein, the term “inhale” may refer to a user inhaling (e.g. dueto an expansion from their lungs) to create a pressure reduction toinduce flow through the flow path.

As used herein, the term “atomizer” may refer to a device to form theaerosol from the precursor. The atomizer may include a heating system,ultrasonic or other suitable system.

As used herein, the term “property of electrical energy through theheating system” or “measured property of electrical energy” may refer toor be based on one or more of the: current; electrical potential; power;phase; other related property, of the electrical energy through and/orover the heating system (e.g. one or more electrically resistiveelements thereof) or a component associated therewith (e.g. a resistor,that may include a shunt resistor, arranged in series with or parallelto the heating system or with other suitable operative arrangement). Italso includes a like property measured through a component differentfrom but arranged in operative proximity to the heating system (i.e. toprovide a representative measure of the electrical energy through theheating system) such as a temperature sensor, which may operate based ontemperature dependent electrical resistance. The property may refer tothe time dependency of the property of the electrical energy.

As used herein, the term “property related to the flow” or “property ofthe flow” may refer to one or more of the following associated with theflow in the flow path: a flow rate (e.g. volumetric or mass) of aerosoland/or air; duration of an inhale; start of an inhale; end of an inhale;intensity of an inhale; flow velocity; a quantity of flow (e.g.volumetric or mass), including one or more components of the aerosol ofthe flow (e.g. nicotine, caffeine) and/or air, which may be associatedwith an inhale.

As used herein, the term “characteristic of the second order timederivative” in respect of the measured property of the electrical energymay include/refer to one or more of the following features: a stationarypoint, e.g. a maximum or minimum; other point of inflection, including asaddle point; a period associated with a stationary point, which may bein respect of a baseline value; a period between stationary points,which may be immediately consecutive or separated, e.g. by a period ofbaseline; a step or other discontinuity; a rise or fall from baseline,e.g. for a pulse; a position associated with an amplitude of a pulse,e.g. 25% of amplitude. The various points may be characterised inrespect of magnitude and/or position in time.

Referring to FIG. 1, embodiment aerosol generation apparatus 2 includesa power supply 4, for supply of electrical energy. The electrical energymay be supplied to an atomizer 6 and/or electrical circuitry 8. Thepower supply 4 may include an electric power supply in the form of abattery and/or an electrical connection to an external power source. Theapparatus 2 may include a precursor transmission system 10 to transmitprecursor to the atomizer 6 for formation of aerosol therefrom. Adelivery system 12 delivers the aerosol to a user.

Referring to FIGS. 1 and 2, embodiment aerosol generation apparatus 2includes the precursor transmission system 10 having a storage portion14 for storage of the precursor. The storage portion 14 may be arrangedas a reservoir (not shown) or other suitable arrangement portiondepending on the physical state of the precursor. The precursortransmission system 10 includes a transmission unit 16 to transmit theprecursor from the storage portion 14 to the atomizer 6. Thetransmission unit 16 may include one or more of: an absorbent member(e.g. cotton) arranged for transmission by capillary action; a conduit;a valve; a pumping system, which may include an electrically operatedpump.

In an embodiment, which is not illustrated, the precursor transmissionsystem 10 may be omitted. In such an embodiment the precursor may bearranged as a consumable pod (e.g. as a liquid or gel), wherein anatomizer includes a heated receptacle for the pod.

The delivery system 12 includes a flow path 18 to transmit aerosol fromthe atomizer 6 to a user. The atomizer 6 includes a precursor inlet 20.The atomizer 6 includes a flow inlet 22 and an outlet 24 of the flowpath 18 for passage of flow through the atomizer 6. In an embodiment,which is not illustrated, the flow path 18 receives aerosol from theoutlet 24 and does not pass through the atomizer 6.

The flow path 18 includes an inlet 26, which may be arranged through ahousing of the apparatus 2. The flow path 18 includes an outlet 28 fordelivery of the aerosol and inlet flow to the user. The outlet 28 may bearranged as a mouthpiece or other suitable delivery member.

The atomizer 6 includes a heating system 30, which may be arranged asone or more electrically resistive heating elements (not shown). Aheating element may be arranged as a wire or filament. A heating elementmay be operatively connected to the precursor transmission unit 16 toheat precursor of the transmission unit 16. The one or more heatingelements may be arranged within and/or in fluid communication with theflow path 18, e.g. to be cooled by said flow.

In an embodiment, which is not shown, a cartomizer integrates a storageportion 14 and transmission unit 16 of the transmission system 10 andheating system 30 in a common housing. The cartomizer including apredetermined amount of the precursor.

The circuitry 8 regulates electrical energy from the power supply 4 tothe heating system 30. Proximal a heating element the precursor may beconverted to a supersaturated vapour, which subsequently condenses toform an inhalable aerosol. As precursor is converted to aerosol, it isreplaced by further precursor supplied by the transmission unit 16, e.g.by a pumping action, until the storage portion 14 is spent.

The electrical energy supplied to the heating system 30 may becontrolled with the circuitry 8 by one of the following or other likecircuitry: pulse width modulation (PWM) via an electrically operatedswitch, or by other suitable means, e.g. by chopping of an alternatingcurrent waveform; a direct current (DC): DC converter, such as a Buckconverter; a linear regulator.

The circuitry 8 implements some form of control of the temperature ofthe heating system 30, e.g. by closed loop control. Depending on theembodiment, the control may comprise regulating one of the: electricalpotential; current; power; temperature; other related quantity to remainat a target value through (or over) the heating system 30.

Since the heating system 30 may include resistive elements arrangedwithin the flow path 18, inhalation through the flow path has the effectof cooling the heating system 30. Said cooling influences the electricalresistance of the resistive elements, and therefore the degree ofcooling can be representative of the intensity of the user inhalation,i.e. the flow rate through the flow path, and since the amount ofprecursor delivered as an aerosol from the transmission unit 16 may havea dependency on the intensity of the inhalation, the resistance can beused to determine the property of the flow as defined herein.

In embodiments wherein the voltage is regulated as constant over theheating system 30, the change in electrical current to maintain aconstant voltage during an inhalation can be representative of theintensity of the inhalation.

In embodiments wherein a temperature of the heating system is regulatedat a target temperature, e.g. by proportional-integral-derivative (PID)or other like control algorithm, the power (or other related quantitysuch as electrical current) to maintain the target temperature during aninhalation can therefore be representative of the intensity of theinhalation.

A temperature of the heating system 30 may be determined by measuringthe electrical resistance as described above and by implementation of anempirically determined relationship between electrical resistance andtemperature. Alternatively, the circuitry may implement a dedicatedtemperature sensor arranged in operative proximity to the heating system30.

It will be understood that the examples presented in the subsequentembodiments may be adapted for the various aforementioned forms ofheating system 30 control.

The circuitry 8 may comprise a trigger (not shown) to detect whenaerosol formation is required. The circuity 8 may effect the supply ofelectrical energy to the heating system 30 upon the determination oftriggering of the trigger. The trigger may detect when a user actionsuggests aerosol formation is required. Such a request may be implicit,such as via inhalation, or explicit, such as via a button press. Thetrigger may comprise an actuator being actuated by physical contact(e.g. a vaping button), including by a digit of a hand of the user.Examples include a button or a dial. The trigger may comprise aninhalation sensor operable to detect user inhalation through the flowpath 18. The inhalation sensor may comprise a flow meter or a pressuresensor operable to determine flow pressure, including by capacitivesensing of a pressure respondent displaceable diaphragm.

Referring to FIG. 3 an embodiment arrangement of the apparatus 2comprises: a cartomizer 32 interconnecting a power supply 4 and amouthpiece 34. The mentioned components may be connected in a modularfashion, including by bayonetted or threaded connection types or othersuitable connection. The apparatus 2 is geometrically elongated along alongitudinal axis. The mentioned components can be arranged in the formof an elongated cylindrical shape, so as to replicate that of a cigar orcigarette. In embodiments, which are not illustrated, the mentionedcomponents are alternatively arranged; e.g. the atomizer may be arrangedseparable from a storage portion. One or more of the mentionedcomponents may be arranged in a common housing 35.

Referring to FIGS. 1-5, an electrically operated aerosol generationsystem 36 for generation of an aerosol may implement features of any ofthe preceding embodiments or other embodiments disclosed herein. Thesystem 36 is configured to generate an aerosol from an aerosol-formingprecursor and comprises the heating system 30 to heat said precursor togenerate the aerosol. The flow path 18 includes the inlet 26 for airinlet and the outlet 28 for delivery of the aerosol and inlet air. Theheating system 30 is arranged in fluid communication with the flow path18, including to receive flow 50 of the flow path.

Electrical circuitry 8 at block 38 determines (e.g. measures) a propertyof electrical energy through the heating system 30. The dependency ofthe property with respect to time may be determined. Examples ofsuitable properties are as disclosed herein, which include current orvoltage. As used herein, the term “determining a property of electricalenergy through the heating system” or “a property of electrical energythrough the heating system” may refer to direct measurement of theproperty of the electrical energy through the heating system and/or arepresentative measurement of the property of the electrical energyelsewhere in the circuitry associated with the heating system (e.g. aresistor in parallel or series with the heating system, which mayinclude a shunt resistor).

The electrical circuitry 8 at block 40 determines a second order timederivative of the determined property of the electrical energy throughthe heating system 30. As used herein, “determination of a second ordertime derivative” or “based on the second order time derivative” (or alike term) may include a representative quantity without explicitformulation, as well as with explicit formulation. Exemplary derivationmethods for the second order derivative will be provided.

Electrical circuitry 8 at block 42 determines a characteristic of thesecond order time derivative, examples of which are as disclosed herein,which include features such as a peak to peak value of maxima andminima. The term “characteristic of the second order time derivative” isto be understood as not limited to a single feature; e.g. it maycomprise said peak to peak value and a time of a maximum; furtherexamples will be provided.

Electrical circuitry 8 at block 44 processes the determinedcharacteristic of the second order time derivative to determine theproperty related to the flow. Examples of the property related to theflow are as disclosed herein, which include an amount of one or morecomponents of the aerosol dispensed during a user inhale through theflow path 18.

In embodiments, the property related to the flow may be determined basedon a relationship between the property related to the flow and thecharacteristic of the second order time derivative; e.g. therelationship may be based on empirical data, examples of which will beprovided. In other embodiments, which are not illustrated, the circuitry8 may implement alternative procedural steps, e.g. a fixed operation isperformed on the characteristic.

Electrical circuitry 8 at optional block 46 outputs the determinedproperty related to the flow, which may include providing instructionsto a user interface to display the determined property and/or to storesaid property, examples of which will be provided.

In accordance with the definition of circuitry 8 herein, it will beunderstood that the process blocks 38-46 (or any other block associatedtherewith and like process steps of other embodiments disclosed herein)may be executed centrally on the apparatus 2 and/or distributed on othercircuitry associated with the system 36, e.g. a peripheral device 48,which may be implemented as a smartphone.

The procedural steps exemplified by the blocks of FIG. 4 will now bedescribed in more detail, commencing with block 38. The circuitry 8 fordetermination of the property of electrical energy through the heatingsystem 30 may be implemented in various manners.

[Determination of Property of Electrical Energy Through the HeatingSystem]

Referring to FIG. 6, the circuitry 8 implements a circuit fordetermining the property of the electrical energy through the heatingsystem 30. The circuitry 8 includes a measurement unit 52 to measure aproperty of the electrical energy through or over a heating element ofthe heating system 30. The measurement unit 52 may be implemented as aresistor (e.g. a shunt resistor, not shown) arranged in series with theheating system 30 and a potentiometer (not shown) arranged to measurethe electrical potential over the resistor. The electrical potentialover the resistor may be converted to current by division of theresistance. Accordingly, the property of the electrical energy throughthe heating system 30 may be based on current and/or electricalpotential. A processor 54 determines the property of the electricalenergy based on a signal from the measurement system 52.

In embodiments, which are not illustrated, the measurement unit may haveother implementations, e.g. a potentiometer arranged to measure theelectrical potential directly over the heating system or other propertythat may include phase or power. Moreover, the processor may implementelements of the measurement unit, e.g. the potentiometer as an algorithmand/or a combinational logic circuit. The processor may also implementelements of a control system to control the electrical energy to theheating system, e.g. for PWM control, or DC:DC conversion. The processor54 may implement determination of the second order time derivative ofthe variation of the property of the electrical energy through theheating system 30 and subsequent determination of a property related tothe flow as will be discussed.

The heating system 30 may comprise a single or multiple heatingelements. The material of the heating element may be selected to have ahigh temperature coefficient of resistance α, e.g. 30-90×10⁴, such asNickel. In the embodiments, the or each heating element of the heatingsystem 30 may be heated to a range to cause vaporisation of theprecursor without combustion of the precursor, e.g. to 150-350° C.

Referring to FIG. 7, which is a more detailed implementation of thecircuitry 8 of FIG. 6, the circuitry 8 includes exemplary componentryfor illustrative purposes. The measurement system 52 is implemented as 2mΩ shunt resistor 58, which is arranged in series with the heatingsystem 30. The heating system 30 has a 200 mΩ electrically resistiveload. An amplifier 60 amplifies the electrical potential over the shuntresistor 58. The amplifier is an INA215 by Texas Instruments with a gainof 50. Filter 62 is arranged to filter the amplifier 60 output, e.g. toremove noise including spurious modes. The processor 54 is implementedas a microcontroller 64. The microcontroller 64 is a CC2540 by Texasinstruments.

A DC-DC converter 56 (which in the embodiment is implemented as a buckconverter) is arranged to provide a stabilised continuous voltage fromthe power supply 4. The DC-DC converter is a LM212 Buck by TexasInstruments. The power supply 4 has a nominal supply of 3.7 V. The DC-DCconverter 56 outputs a continuous voltage of 2.5V, but may be controlledto 1.9-2.75V. The microcontroller 64 provides control of the DC-DCconverter 56. A potentiometer 66 is arranged to provide a referencevoltage to the microcontroller 64 and DC-DC converter 56. Thepotentiometer 66 is an MCP4013 by Microchip. The voltage is controlledby the microcontroller 64, which sets the reference voltage of thepotentiometer 66.

Since the resistance of the shunt resistor 58 is relatively constant,the electrical potential over the shut resistor 58 may be converted tocurrent by division of said resistance. Accordingly, the property of theelectrical energy through the heating system 30 may be based on currentand/or electrical potential, or other quantities that may be derivedtherefrom, such as power.

It will be understood that the second order time derivative of thedetermined property of the electrical energy through the heating system30 is relatively independent of the specific implementation (e.g.resistances) of components of the circuitry 8. Moreover, saidindependence may reduce any effect of variations of electricalcomponentry (e.g. manufacturing tolerances) implementing the samecircuitry 8, e.g. for batches of the same apparatus 2.

The filter 62 may be implemented as a low pass filter, e.g. aresistor-capacitor (RC) filter. The pass frequency may be below 20 Hz.In an embodiment, the filter (or an additional filter) is implemented asa digital filtering algorithm (or logic circuit) optionally arranged onthe processor 54. A digital filter can advantageously be fieldconfigured by the processor 54. The filter may implement a smoothingalgorithm to increase signal-to-noise ratio with minimal distortion; asuitable implementation includes a Savitzky-Golay filtering algorithm.In an embodiment, the filter is selected to filter out oscillations dueto bubbles in the reservoir or other fluctuations.

[Example of Measured Property of Electrical Energy Through HeatingSystem]

Referring to FIGS. 8-11, line 72 represents the time dependency ofelectrical current through the heating system 30 when measured using theembodiment circuitry 8 shown in FIG. 6 or 7. A similar time dependencymay be obtained when measuring other properties of the electrical energythrough the heating system; examples include power.

In the embodiment (as discussed previously), a constant electricalpotential is maintained over the heating system 30. The electricalcurrent through the heating system 30 causes the or each heating elementthereof to heat up. The temperature increase of the heating elementcauses a resistance increase, which due to regulation of a constantelectrical potential has a resultant effect of decreasing the electricalcurrent through the heating system 30.

Referring to FIG. 8, at T₀ the electrical energy is applied to theheating system 30. It can be observed that the electrical currentthrough the heating system 30 decreases in an exponential manner. Thisis due to the heating system 30 exhibiting a substantial initialtemperature increase as it is heated, followed by convergence to aconstant temperature. Since the electrical resistance is proportional tothe temperature, to maintain the constant electrical potential, thecurrent exhibits corresponding exponential decay.

In an embodiment, which is not illustrated, the circuitry 8 implements aconstant current source, which is arranged to maintain a constantcurrent over the heating system 30. As the resistance of the heatingelement increases, the electrical potential over the constant currentsource increases, thus the electrical potential exhibits a similar timedependency as for the electrical current of the preceding embodiments. Asimilar time dependency may be obtained when measuring the power overthe heating system or other representative quantity. It will thus beunderstood that the relationship between the property of electricalenergy through the heating system 30 and the property related to theflow of the flow path may apply to various electrical quantities thatare selected based on the implementation of the circuitry 8.

When a user inhales through the flow path 18, heat is dissipated fromthe heating system 30 to the flow 50, e.g. by convective heat transferof thermal energy from the heating element to the flow stream. The heatdissipation of the heating system 30 is thus related to the flow 50through the flow path 18. Since the temperature of the heating elementis related to its electrical resistance, the temperature thus influencesthe property of the electrical energy through the heating system 30(e.g. the electrical potential over the heating system 30 or currentthrough the heating system 30 depending on the implementation of thecircuitry 8). The electrical energy through the heating system 30 isthus related to various properties of the flow 50 in the flow path 18 aswill be discussed.

Referring to FIGS. 10 and 11, the influence of a user inhale through theflow path 18 on the electrical current is more clearly illustrated,wherein line 72 shows the current during an inhalation and line 73 showsthe current in absence of an inhalation. Line 78 is the second ordertime derivative of line 72. In particular at reference lines 74 and 76 auser inhalation is initiated and terminated respectively. It can be seenthat the initiation of the inhale causes an initial oscillation 75 inthe current followed by a period of increased current 77 and anoscillation 79 at termination. The effect is more pronounced in thesecond order time derivative 78 of the current. At line 81 the initialoscillation 75 ceases to have an effect on the second order timederivative 78. At line 83 the termination oscillation 79 initiates aneffect on the second order time derivative 78.

Referring to FIGS. 8 and 9, the current decreases from an initialmagnitude of over 12 amps to: 8.5-7.5 amps between 0.5 and 1 seconds;7.5-7 amps between 1 and 2 seconds; a nominal value of 6.5-7 amps afterabout 2 seconds. With the nominal value as a reference, current thusfalls by over 70% in the first 0.5 seconds. It may be preferable tomeasure the effect of the user inhale on the current through the heatingsystem 30 following 0.5 seconds, wherein the current has stabilised andthe effect of the oscillations due to inhalation may appear morepronounced.

It is thus desirable that the user inhale occurs following the supply ofa predetermined amount of electrical energy and/or with some preheatingof the heating element to enable the effect of the initiation of theuser inhale to be captured.

A used herein “nominal value” may refer to a normal operating value of asignal of the electrical energy, which the circuitry 8 may be designedto operate with. Nominal may refer to a value that the signal convergesto or about.

Referring to FIG. 12, circuitry 8 implements an embodiment process forstabilising a property of the electrical energy through the heatingsystem 30. The process may be implemented in combination with theembodiment process illustrated in FIG. 4, or another embodimentdisclosed herein. At block 88 the circuitry 8 applies a predeterminedamount of electrical energy to the heating system 30. At block 90 thepredetermined amount of electrical energy stabilises the property ofelectrical energy (e.g. the current in the exemplary embodiment) throughthe heating system 30. At block 92 the circuitry 8 determines a propertyrelated to the flow 50 of the flow path 18 based on the property of theelectrical energy through the heating system 30 subsequent to theapplied predetermined amount of electrical energy, i.e. with saidproperty stabilised, examples of which will be provided.

Inhalation (which may include initiation of inhalation) followingapplication of the predetermined amount of electrical energy may beensured by implementing one or more embodiment modes of operation of thecircuitry 8. In an embodiment, at block 86, the predetermined amount ofelectrical energy is applied upon determination of a trigger aspreviously described. The trigger may comprise an actuator actuated byphysical contact (e.g. a vaping button), including by a digit of a handof the user. The electrical circuitry 8 may implement the actuator withelectrical energy applied to the atomizer 6 for the duration of theactuation. It has been found that with such an actuator most usersinitiate inhalation after 0.5 or 1 seconds of actuation. Thus, thecircuitry 8 can be specifically configured to apply the predeterminedamount of electrical energy before 0.5-1 second. Said configuration canbe implemented by the control system of the processor 54 for regulationof electrical energy to the heating system 30 (e.g. the DC:DC converteror PWM based control system applies the predetermined amount ofelectrical energy in the first 0.5-1 second or other suitable timeperiod T₁).

In other embodiments, the circuitry 8 implements the trigger as a motionsensor or facial recognition sensor (e.g. a camera with imageprocessing) to determine intent to initiate an inhalation.

In an embodiment, the circuitry 8 may implement enabling of inhalationthrough the flow path 18 only when the heating system 30 is heated to apredetermined temperature and/or the current is within a particularrange of the nominal value (e.g. ±40% or ±25%). The circuitry 8 mayenable inhalation by means of an electrically operated value or otherflow regulation device.

Referring to FIGS. 8 and 9, the circuitry 8 applies the predeterminedamount of electrical energy over the first time period T₁. Initiation ofthe inhale through the flow path 18 is indicated by line 74 at T_(i),which occurs after T₁ and during a subsequent time period. The circuitry8 thus determines the property related to the flow through the flow pathas will be discussed. The circuitry 8 may be configured to apply thepredetermined amount of electrical energy over a T1 duration of 0.3-2,or 0.6-1.5 or less than 1 or 0.5 seconds.

Whilst it is preferable to ensure T_(i) occurs after the predeterminedamount of electrical energy has been applied, in an embodiment theproperty of the flow is based on an oscillation at termination of theinhalation (examples of which will be provided); thus, in some examples,the T_(i) occurs before the predetermined amount of electrical energyhas been fully applied.

The predetermined amount of electrical energy may be 20, 25 or 30 Joules(each ±40% or ±25% or ±10%). In the embodiment implementations of FIGS.6 and 7, the predetermined amount of electrical energy can include 2.5Vapplied for T₁ (as defined by the previous ranges).

The predetermined amount of electrical energy may be to preheat aheating element of the heating system 30 to a predetermined temperaturerange from which may be cooled during said inhale. The predeterminedtemperature range may be selected to cause vaporisation of the precursorwithout combustion of the precursor, e.g. to 150-350° C. or 200-250° C.The temperature of the heating element may be determined by variousimplementations, which include: resistance of the heating system; adedicated temperature sensor; empirical data (e.g. a particular amountof energy is known to effect an experimentally determined temperaturerange).

The predetermined amount of electrical energy may be to stabilise theproperty of the electrical energy through the heating system 30 to ±25%or ±40% of the nominal value. In the example the nominal value of thecurrent may be taken as 6.5 amps, thus +40% or +25% equates to 9.1 ampsand 8.1 amps respectively, 8.1 amps occurs during T₁. The same rangesmay be applied to other properties (e.g. electrical potential) of theelectrical energy through the heating system 30 in other embedmentimplementations of the circuitry 8.

The predetermined amount of electrical energy may be to stabilise theproperty of the electrical energy through the heating system so thatoscillations caused by the user inhale through the flow path can beextracted and processed. The oscillations may include those in a firstor second order time derivative as will be discussed.

The specific amount of electrical energy to achieve the aforementionedstabilisation will depend on the implementation of the apparatus 2,which includes implementation of: the circuitry 8; heating system 30,including the resistance of the heating element; the flow path. Thus, itwill be understood that the specific amount of electrical energy may bedetermined based on empirical data.

Referring to FIG. 9, after approximately 2.5 seconds the current 72exhibits notable oscillation (which can be more clearly seen in thecorresponding second order time derivative 74). The oscillation iselectrical noise caused by overheating of the heating element of theheating system 30. It may therefore be desirable to configure thecircuitry 8 such that the user inhale through the flow path 18 occursprior to the electrical noise, such that the electrical noise may notinterfere with measurement of the inhale. This may be achieved byapplication of the predetermined amount of electrical energy as close toinitiation of the user inhale as possible.

Since the second order time derivatives are particularly vulnerable tointerference as the electrical energy through the heating system 30decreases from its initial value to the nominal value, it may bedesirable to implement circuitry 8 that applies the predetermined amountof electrical energy in combination with processing of the second ordertime derivative to calculate the property of the flow, examples of whichwill be provided.

However, in some embodiments, the property of the electrical energythrough the heating system 30 without numerical differentiation may beprocessed to calculate the property of the flow, examples of which willbe provided.

[Determination of Second Order Time Derivative]

Referring FIGS. 4, and 9-11, the circuitry 8 at block 40 determines asecond order derivative with respect to time of the determined propertyof the electrical energy through the heating system 30.

Determination of the second order time derivative may be implemented byan algorithm (or logic circuit), which may be arranged on the processor.The finite difference method (e.g. Newton's difference quotient,symmetric difference or a higher-order method), or other methods such asdifferential quadrature, may be implemented. Derivation of thederivative may also be determined by electrical componentry, e.g. afinite difference method is implemented by a capacitor arranged tointroduce a delay in the property of the electrical energy through theheating system 30 and a differential amplifier to determine a derivativefrom the property of the electrical energy and delayed property of theelectrical energy.

It will be understood that explicit determination of the second ordertime derivative is not required, e.g. when implementing a finitedifference method, the small change in time may not be divided by if thechange in time between the function sampling points remains constant. Inembodiments explicit formulation of the derivative is implemented.

[Determination of Characteristic Feature of the Second Order TimeDerivative]

Referring to FIG. 4, at block 42 the characteristic feature of thesecond order time derivative may be extracted by the circuitry 8,including by an algorithm (or logic circuit) arranged on the processor.

The specific characteristic to be extracted may depend on the particularrelationship that is implemented to determine the property of the flowof the flow path 18, examples of which will be provided.

The relationship may require extraction of a class comprising one ormore features (referred to as input values), of the second orderderivative, all of which are encompassed by the term “characteristicfeature of the second order time derivative”.

It will be understood that depending on the specific class to beextracted, various processes for feature extraction may be implemented,e.g. stationary points or initial rises/falls from baseline can bedetermined via comparison of a magnitude of a data point to an adjacentdata point, a peak to peak amplitude of adjacent maxima and minima or anamplitude of a maximum or minimum may subsequently be determined.

[Determine Property of Flow]

Referring to FIG. 4, at block 44 the determined characteristic featureof the second order time derivative is processed to determine theproperty of the flow. Processing may include the implementation of aparticular relationship to determine the property of the flow 50 of theflow path 18. The relationship can be implemented by the circuitry 8,including by an algorithm (or logic circuit) arranged on the processor.

As used herein the term “relationship” may refer to a relationshipbetween the property of the electrical energy through the heating system30 and the property of the flow of the flow path 18. The relationshipmay be an empirical relationship, e.g. one obtained by experimentallyobtained data. The empirical data can be stored on a memory associatedwith the circuitry 8. Thus, in embodiments, an “empirical relationship”may also be referred to as a “stored relationship”, and the terms“empirical” and “stored” may be used interchangeably. The relationshipmay include a mathematical function, with one or more input variablesand an output variable. The output variable comprises the property ofthe flow. The one or more input variables comprises the previouslydescribed class of one or more characteristics.

A range of suitable output values is provided under the definition ofthe “property related to the flow”. A range of suitable input values(i.e. a class) is provided under the definition of the “characteristicof the second order time derivative”, and/or other features of theelectrical energy through the heating system 30.

The herein defined relationships may be better understood in view of thefollowing example:

EXAMPLE 1

An exemplary embodiment that implements one or more features of thepreviously described embodiments, or another embodiment disclosedherein, will now be provided.

The relationship provided in equation (1) may be implemented bycircuitry 8 to determine the property of the flow,

M=A.I ² +B.I+C.T _(i) +D.T _(d) +E.V−F  (1)

wherein the output value is the mass M of aerosol present in a userinhale through the flow path 18. Coefficients A-F are determined byregression of empirical data and have the respective values: 0.5965;0.1223; 0.002088; 0.0004042; 0.05651; 134.0. Referring to FIG. 9, theinput values comprise: a peak to peak magnitude 84, which is denoted as“I”; the constant voltage maintained over the heating system 30, whichis denoted as “V” in mV; the duration of the electrical energy appliedto the heating system “T_(d)” in mSec; the initiation time of theinhalation “T_(i)” in mSec. Since the voltage Vis generally a constant,E and V may be replaced as a single coefficient.

The above relationship will now be utilised by way of example:

The input values include: a voltage V of 2.51 V; a duration of theelectrical energy T_(d) of 3.987 seconds; T₁ of 1.035 seconds; anintensity I of 1.370. The above relationship determines M as 12.9 mgwith an experimental error of ±2-3%. The experimentally obtained valueof M was obtained by measuring the depletion of a storage portioncontaining the precursor. A user inhale through the flow path wasreplicated by a pump with a calibrated representative flow rate of 18.33ml/s.

The amount of individual components of the aerosol, e.g. nicotine, canbe determined based on their concentration in the precursor, e.g. by theproduct of the concentration and M.

Referring to FIG. 9, it can be seen that, by using the second order timederivative, characteristics (e.g. the stationary points) are morepronounced for line 74 (than what would be observed for the first ordertime derivative or line 72). The derivative 74 is processed to determinethe peak to peak magnitude 84 for an adjacent maximum 80 and minimum 82,which is associated with initiation of the inhale. The initiation ofinhale is determined as the maximum 80 as indicated by line 74.

The circuitry 8 may implement various conditions to search and locatethe correct maximum 80 and minimum 82. These are exemplified for theimplementation of the circuitry 8 shown in FIG. 7 as: determine possiblemaxima and minima for 1.5 seconds following initiation of the electricalenergy to the heating system; determine greatest difference betweenadjacent maxima 80 and minima 82; disregard if time difference betweenadjacent maxima 80 and minima 82 is greater than 1 second; disregard ifthe absolute of peak to peak 84 is not greater than 0.19; the absoluteof peak to peak 84 must be greater than that of an absolute of the peakto peak of a later occurring adjacent maximum and minimum multiplied by1.18; the absolute of peak to peak 84 must be greater than that of anabsolute of the peak to peak of an earlier occurring adjacent maximumand minimum multiplied by 1.13.

The circuitry 8 may determine the time duration T_(d) of the electricalenergy being applied to the heating system 30 by the previouslydescribed duration of actuation of the trigger (e.g. the vaping buttonor other suitable trigger). The circuitry 8 may determine the initiationof inhalation T_(i) by the time of the maxima 80. A representative timeduration of inhalation (which is not used in equation 1) may bedetermined by T_(d)−T_(i).

Referring to FIGS. 10 and 11, which exemplify the current 72 and secondorder time derivative 78 for instances where the inhalation is initiatedwhen the current has achieved the nominal value and is converging to thenominal value respectively, it can be seen that the peak to peak 84 mayexhibit a similar magnitude in both instances. It may therefore beadvantageous to utilise the second order derivative (as opposed to thefirst order derivative, or current without numerical differentiation)for determination of input values. Any dependency of the peak to peakmagnitude 84 and the initiation time T_(i) (due to exponential decay ofthe current) may be accounted for based on the dependence of Equation(1) on the initiation time T_(i). Moreover, it is apparent that thesecond order derivative converges faster to a nominal value than currentwithout numerical differentiation.

In a variant of Equation (1), if the inhalation is initiatedsufficiently early, a saddle point in the current 72 may occur at line74; consequently, the relationship may be adapted to search for a saddlepoint and to utilise the initiation of the point of zero gradient in thesaddle (instead of the maxima at 80) to derive the peak to peak 84.

EXAMPLE 2

An exemplary embodiment that implements one or more features of thepreviously described embodiments, or other embodiment disclosed herein,will now be provided.

The relationship provided in equation (2) may be implemented bycircuitry 8 to determine the property of the flow,

M=X.T _(d) +Y.V−Z  (2)

wherein the output value is the mass M (in mg) of aerosol present in auser inhale through the flow path 18. Coefficients X−Z are determined byregression of empirical data and have the respective values:−0.00003115; 0.1227; 295.2. The input values comprise: the constantvoltage maintained over the heating system 30, denoted as “V” (in mV);the duration of the electrical energy applied to the heating system“T_(d)” (in mSec).

The above relationship will now be utilised by way of example:

The input values include: a voltage V of 2.51 V; a duration of theelectrical energy T_(d) of 3.987 seconds. The above relationshipdetermines M as 12.7 mg with an experimental error of ±4-6%. Theexperimentally obtained value of M was obtained by measuring thedepletion of a storage portion containing the precursor. A user inhalethrough the flow path was replicated by a pump with a calibratedrepresentative flow rate of 18.33 ml/s.

The duration of the electrical energy T_(d) through the heating system30 can be determined as discussed for Example 1.

In instances wherein initiation of inhale cannot be determined (e.g. themaxima 80 cannot be identified), thus precluding implementation ofEquation (1), then Equation (2) may be implemented to determine theproperty of the flow.

Variant Examples

It is to be understood that Example 1 and Example 2 provide examplerelationships between the electrical energy through the heating system30 and the property of the flow of the flow path 18. Other relationshipsmay be implemented.

A variant of Example 1 may include, as input values, one or more of: theperiod between the maximum 80 and minimum 82, or other period relatedthereto; the area under the maximum 80 and/or minimum 82; a magnitude ofthe maximum or minimum 82 (as opposed to the peak to peak value 84);alternative maxima and or minima may be used, including those associatedwith the end of the inhale. Alternatively, a gradient/period of theperiod between the oscillations caused by initiation and termination ofinhalation may be utilised. In other variants, the input values may beobtained from a first derivative of the property of the electricalenergy through the heating system 30, or of the property of theelectrical energy through the heating system 30 (i.e. without numericaldifferentiation).

In a further variant, a feature of an oscillation in a property of theelectrical energy through the heating system may be used as an inputvalue, including as the only input value; e.g. Equation (1) is adaptedto have, as the only input value, the peak to peak 84, which may bebased on empirical data, which thus replaces the time dependency in theequation.

In a further variant, the duration of the user inhale may be obtainedfrom the second order time derivative and may be used as an input valueinstead of the initiation time of the inhalation and/or duration of theelectrical energy applied to the heating system.

A variant of Example 2 may include, as an input value, the duration ofthe user inhale, which may be determined from the second derivative ofthe property of the electrical energy through the heating system 30, orthe property of the electrical energy through the heating system 30(i.e. without numerical differentiation).

In other variants an alternative property related to the flow may bedetermined; e.g. equations (1) or (2) may be alternatively formulated todetermine: volume of aerosol; mass or volume of flow (i.e. the summationof the aerosol and air); velocity of the flow.

[Output of Property Related to Flow]

The determined property of the flow may be utilised in various manners,depending on what it is. It may be utilised as one or more of thefollowing: display to a user on a user interface (e.g. on a peripheraldevice, such as a smartphone 48, or on the apparatus 2); stored on amemory associated with the system 36; used as a basis for control of theapparatus 2 (e.g. it is determined that the depletion of precursor isgreater than a threshold and aerosol generation is reduced or otherwisecontrolled).

Referring to FIG. 5, in embodiments where the property of the flow isdisplayed on a user interface 94, the circuitry 8 generates instructionsfor the user interface 94 to display information based on the determinedproperty of the flow. The instructions may be for processing, by adisplay driver, for driving the user interface 94. In embodimentswherein the property of the flow is an amount of one or more componentsof the aerosol present in an inhale, the quantity of said amount(s),and/or the amount from an aggregate of a plurality of inhales, may bedisplayed.

[Determination of Property Related to Flow Based on Initiation orTermination of User Inhale Through Flow Path]

Referring to FIG. 13, the described embodiments include circuitry 8 atblock 100, to determine a property of electrical energy through theheating system 30; at block 102, the circuitry 8, to determine anoscillation due to initiation and/or termination of a user inhalethrough the flow path 18. The process may be implemented in combinationwith the embodiment process illustrated in FIG. 4, and/or 12, or anotherembodiment disclosed herein.

As used herein “oscillation” may refer to one or more of: maxima;minima; saddle point. The maxima and minima may be adjacent. Theoscillation may be caused by an inhalation through the flow path 18(rather than by electrical noise or other interference). Furthermore, inembodiments, “oscillation” may refer to a certain feature or pattern ofa parameter, such as (but not limited to) a feature or pattern of aproperty of electrical energy through the heating system. Referring toFIGS. 9 to 11, such a property may be, e.g., a current over time, and/ora first/second order derivative thereof. Hence, in such embodiments, an“oscillation” may occur at a portion of a function of a property, suchas the functions illustrated by the graphs in FIGS. 9 to 11. Forexample, in FIG. 9 the portions of graphs 72 and/or 78 between line 74and the vertical line (not shown) through point 82, or relatively closethereto, may be referred to as an “oscillation”. Referring to FIGS. 10and 11, an “oscillation” may be seen in the portions of graphs 72 and/or78 between lines 74 and 81 or between 83 and 76.

As used herein, an “area of an oscillation” may refer to an area atleast a section of whose boundary is formed by at least a section of thegraph over time representing the oscillation. In an example, referringto FIG. 10, the area of the oscillation represented by the portion ofgraph 78 between lines 80 and 82 may thus refer to an area which is onone side bounded by the entire or part(s) of the portion of graph 78between lines 80 and 82. Other sides of the area may be bounded byhorizontal lines, such as the axis in the coordinate system which isdenoted by “t” (the time axis) and/or by vertical lines, such as dashedlines 74 and 81 (or their extensions); or any other lines that aresuited to define boundaries of an area.

As used herein, a “maximum” (of or comprised by an oscillation) mayrefer to a local maximum. Similarly, in embodiments, a “minimum” (of orcomprised by an oscillation) may refer to a local minimum. In anexample, referring to FIG. 10, the local maximum 80 and/or 108 of theoscillation as described above may be referred to as a “maximum”.Similarly, the local minimum 82 and/or 110 of the oscillation asdescribed above may be referred to as a “minimum”. As can be seen inthese examples, in preferred embodiments, an oscillation is bounded by aminimum and/or a maximum.

As used herein, an “amplitude” may refer to the absolute difference of aproperty of electrical energy through the heating system betweendifferent points of time. In an example, referring to FIG. 10, an“amplitude” may thus refer to the difference between a “maximum” and/ora “minimum” (peak to peak amplitude) as described above, such asillustrated by references 84 or 112. Alternatively, an “amplitude” mayrefer to the distance of a maximum or a minimum from the time axis (peakamplitude).

In embodiments, a “period of an oscillation” may refer to a duration ofan “oscillation” as described above. Thus, in an example, a “period” maystart and end at the endpoints of a respective “oscillation”. However,the startpoint and endpoint of the oscillation may be freely chosen.

Referring to FIG. 13, at block 104, the circuitry 8 is configured toprocess one or more features of the oscillation to determine a propertyrelated to flow. The processing may include the one or more featuresused as the input values for the described relationship between theproperty of the electrical energy through the heating system 30 and theproperty of the flow of the flow path 18, with the property of the flowbeing the output value. At block 106, the circuitry 8 is configured tooptionally output the property related to flow (as discussedpreviously).

Referring to the previously discussed Example 1, the property related tothe flow of block 104 may include an amount of one or more components ofaerosol dispensed in the inhale through the flow path 18. As discussedfor Example 1, and with reference to FIGS. 10 and 11, an input value canbe determined from the oscillation due to initiation of a user inhalethrough the flow path 18. The oscillation may be based on the secondorder time derivative 78, and includes a maximum 80 and an adjacentminimum 82. The peak to peak amplitude 84 can be extracted from themaximum 80 and minimum 82 and used as the input value.

In an embodiment, an input value can be determined from the oscillationdue to termination of a user inhale through the flow path 18. Theoscillation may be based on the second order time derivative 78, andincludes a maximum 108 and an adjacent minimum 110. The peak to peakamplitude 112 can be extracted from the maxima 108 and minima 110 andused as the input value.

It has been found that the oscillation from either or both theinitiation and termination of the inhale are related to an amount of oneor more components of aerosol dispensed in the inhale through the flowpath 18. In embodiments, input values may be determined from theoscillation due to termination and initiation. In embodiments, inputvalues from one of the oscillation due to initiation or termination ofthe inhale may be used if the other is not available.

It will be understood that the implemented relationship between theelectrical energy through the heating system 30 and the property of theflow of the flow path 18 can be selected, based on which input valuesare determined.

Referring to FIG. 9, after approximately 2.5 seconds, the current 72exhibits notable oscillation (which can be more clearly seen in thecorresponding second order time derivative 74). The oscillation iselectrical noise caused by overheating of the heating element of theheating system 30. Depending on when the electrical noise occurs, theelectrical noise may interfere with determination of the oscillationassociated with the initiation and/or termination of inhalation. It maytherefore be desirable to configure the circuitry 8 such that the userinhale through the flow path 18 occurs prior to the electrical noise,such that the electrical noise may not interfere with measurement of theinhale.

Referring to FIG. 9, the oscillation due to termination of inhale isinterfered with by the electrical noise. It may therefore be difficultto accurately determine the oscillation due to termination ofinhalation. Accordingly, it may be desirable to implement relationships(e.g. those discussed under Example 1) between the electrical energythrough the heating system 30 and the property of the flow of the flowpath 18 which do not require determination of the oscillation attermination of inhalation and require determination of oscillation atthe initiation, since this oscillation is less likely to be subject tointerference.

In variants, for determining the oscillation, the first derivative ofthe property of the electrical energy through the heating system 30 orthe property of the electrical energy through the heating system 30(i.e. without numerical differentiation) may be utilised.

However, with reference to FIG. 10 it can be seen that the second orderderivative provides a more pronounced oscillation and may yield moreaccurate output values.

In embodiments, the circuitry 8 may determine the oscillation due toinhalation and/or termination of the inhalation by comparison to one ormore predetermined conditions, which are exemplified under Example 1 inrelation to conditions to search and locate the maxima and minima.

In variants embodiments, other features of the oscillation may beutilised as the input value, e.g. the period between the maxima andminima, or other periods related thereto; the area under the maximaand/or minima; a magnitude of the maxima or minima (as opposed to thepeak to peak value).

Considering Example 1, it can be understood that the magnitude of theamplitude 84 is directly related to an amount of the one or morecomponents M of aerosol dispensed, i.e. via the empirical relationshipof Equation 1; the greater the magnitude of the amplitude the greaterthe amount of the component dispensed, e.g. via direct proportionalityor other mathematical function relationship.

[Plurality of Relationships to Determine Property of Flow Implemented byCircuitry]

The described embodiments may be implemented with the electricalcircuitry 8 to determine a property related to the flow of the flow path18 based on one of a plurality of different relationships between theelectrical energy through the heating system and said property.

In particular, the circuitry may implement a process comprising:measuring a property of the electrical energy through the heating system(e.g. the current as described previously or another property such aspower or voltage); determining one or more characteristics from saidmeasured property of the electrical energy (e.g. the input values forthe previously described Example 1 or Example 2 or the herein describedrelated variants or other like characteristics); selecting, based on thedetermined characteristics, one from a plurality of different empiricalrelationships between the measured property of the electrical energy anda property of the flow as defined herein (e.g. selecting Example 1 orExample 2 or another of the herein described related variants);implementing said relationship to determine the property of the flow asdefined herein.

Suitable examples of relationships are provided as Example 1 and Example2 and the herein described related variants. Accordingly, in anembodiment, the circuitry 8 may implement the relationship (e.g. Example1 or Example 2 or other variant) according to an order of preference ora set of input values, which may be referred to as a “class”.

Referring to FIG. 14, an embodiment process for implementing theplurality of relationships includes, at block 114, the circuitry 8measuring the property of the electrical energy through the heatingsystem 30 (examples of which were previously discussed).

At condition 116, the circuitry 8 determines whether a first class ofone or more input values can be determined from the determined propertyof the electrical energy through the heating system 30. If the firstclass can be determined, then block 118 is executed to output theproperty of the flow at block 120. Block 118 implements a firstrelationship.

In an embodiment which implements Equation (1) of Example 1, the firstclass would be: the peak to peak magnitude 84, which is denoted as “I”;the constant voltage maintained over the heating system 30, which isdenoted as “V”; the duration of the electrical energy applied to theheating system “T_(d)”; the initiation time of the inhalation “T_(i)”.Hence at condition 116, if the first class can be determined, then atblock 118 Equation (1) is implemented. At block 120 the output value isthe mass M of aerosol present in a user inhale through the flow path 18.

If at condition 116 the first class cannot be determined (e.g. one ormore of the input values cannot be computed), then condition 122 isexecuted. At condition 112 the circuitry 8 determines whether a secondclass of one or more input values can be determined from the determinedproperty of the electrical energy through the heating system 30. If thesecond class can be determined, then block 124 is executed to output theproperty of the flow at block 120. Block 124 implements a secondrelationship.

In an embodiment which implements Equation (2) of Example 2, the secondclass would be: the duration of the electrical energy applied to theheating system “T_(d)”. Hence, at condition 116, if the second class canbe determined, then at block 124 Equation (2) is implemented. At block120 the output value is the mass M of aerosol present in a user inhalethrough the flow path 18.

In variant embodiments, a greater number than two relationships areimplemented. In embodiments, the classes associated with a plurality ofrelationships may be determined, with the particular relationshipimplemented according to an order of preference.

If at condition 116 the second class cannot be determined (e.g. one ormore of the input values cannot be computed), then block 126 isexecuted. At block 126 the circuitry 8 may determine the output valuebased on an output value determined from one or more prior user inhalesthrough the flow path 18 (e.g. the output value from the previousinhalation is utilised as the output value or an average or othersuitable representation based on output values from a plurality of priorinhalations is utilised as the output value). The information relatingto prior output values may be stored on a memory communicatively coupledto a processor of the circuitry 8.

Referring to the preceding embodiment in which Equation (1) and (2) wereimplemented as the first and second relationships, the input values ofthe second class associated with the second relationship is a subset ofthe input values of the first class associated with the firstrelationship. Electrical circuitry 8 implemented in this manner allowsthe second relationship to be conveniently implemented using one or moreof the input values of the first class in the event that all of thosefrom the first class cannot be determined. Such an implementation mayhave reduced processing overhead.

Embodiments are also provided according to the following clauses:

Clause 1. An aerosol generation system (36) for generation of an aerosolfrom an aerosol-forming precursor, the system comprising: anelectrically operated heating system (30) to heat said precursor togenerate the aerosol; a flow path (18) for transmission of flow,including the aerosol, to a user; the heating system arranged in fluidcommunication with the flow path; electrical circuitry (8) to determinea characteristic associated with a second order time derivative of aproperty of electrical energy through the heating system, and todetermine a property related to the flow of the flow path based on thecharacteristic of the second order time derivative.

Clause 2. The system of clause 1 or another embodiment disclosed herein,wherein the property of the electrical energy is based on one or moreof: electrical current through the heating system (30); electrical powerthrough the heating system; electrical potential over the heatingsystem.

Clause 3. The system of any preceding clause or another embodimentdisclosed herein, wherein the property related to the flow is one ormore of: an amount of one or more components of the aerosol or flow,which may be measured by mass or volume; a start of an inhale; an end ofan inhale; a duration of an inhale.

Clause 4. The system of any preceding clause or another embodimentdisclosed herein, wherein the characteristic of a second order timederivative is based on a property of an oscillation (80, 82) in thesecond order time derivative.

Clause 5. The system of any clause 4 or another embodiment disclosedherein, wherein the oscillation comprises a maxima and adjacent minimaassociated with initiation and/or termination of a user inhale throughthe flow path. Adjacent may refer to immediately proximate, which mayinclude without a period of baseline adjoining the maxima and minima.

Clause 6. The system of any clause 5 or another embodiment disclosedherein, wherein the characteristic is a peak to peak amplitude (84) ofthe maxima and adjacent minima.

Clause 7. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to applyelectrical energy to preheat the heating system (30) prior to a userinhale through the flow path (18).

Clause 8. The system of any preceding clause or another embodimentdisclosed herein, wherein the circuitry (8) to determine the property ofthe electrical energy through the heating system (30) during a userinhale through the path.

Clause 9. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to generateinstructions for a user interface to display information based on thedetermined property of the flow.

Clause 10. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to determine theproperty related to the flow based on a stored relationship between theproperty related to the flow and the characteristic associated with asecond order time derivative. The relationship may include an empiricalrelationship.

Clause 11. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) includes one ormore electronic processors communicatively coupled to a memory.

Clause 12. The system of any preceding clause or another embodimentdisclosed herein, wherein the system (36) includes housing (35) arrangedto house at least part of the flow path (18), the heating system (30)and a precursor transmission unit (16) for transmission of precursor tothe heating system (30) from a storage (14).

Clause 13. A method of determining a property of a flow of an aerosolgeneration system (36). The method may include the system of anypreceding clause or another embodiment disclosed herein. The methodcomprising: determining a characteristic associated with a second ordertime derivative of a property of electrical energy through a heatingsystem; determining the property related to the flow based on thecharacteristic of the second order time derivative.

Clause 14. An aerosol generation system (36) for generation of anaerosol from an aerosol-forming precursor. The system may include thesystem any preceding clause or another embodiment disclosed herein. Thesystem comprising: an electrically operated heating system (30) to heatsaid precursor to generate the aerosol; a flow path (18) fortransmission of flow, including the aerosol, to a user; the heatingsystem arranged in fluid communication with the flow path; electricalcircuitry (8) to apply at least a predetermined amount of electricalenergy to the heating system to stabilise a property of electricalenergy through the heating system, the electrical circuitry to determinea property related to the flow of the flow path based on the stabilisedproperty of the electrical energy through the heating system. Thestabilised property may be subsequent to the applied predeterminedamount of electrical energy.

Clause 15. The system of clause 14 or any preceding clause or anotherembodiment disclosed herein, wherein the electrical circuitry isoperable to apply the predetermined amount of electrical energy over afirst time period, and to determine the property related to the flowover a subsequent second time period.

Clause 16. The system of any preceding clause or another embodimentdisclosed herein, wherein the first time period is between 0.3 and 2 or0.6-1.5 seconds.

Clause 17. The system of any preceding clause or another embodimentdisclosed herein, wherein the predetermined amount of electrical energyis at least 10-50 or 15-40 Joules±40% or ±20%.

Clause 18. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to determine useractuation of a trigger an in response to apply said predetermined amountof electrical energy through the heating system (30). The trigger may bea manually actuated actuator, which may be for actuation by a digit of ahand of a user, e.g. a button.

Clause 19. The system of any preceding clause or another embodimentdisclosed herein, wherein the predetermined amount of electrical energyis to preheat the heating system (30) to a predetermined temperaturerange. The temperature may be reduced by thermal energy transfer intothe flow during a user inhale through the flow path. The predeterminedtemperature range may be 150-350° C.

Clause 20. The system of any preceding clause or another embodimentdisclosed herein, wherein the property of electrical energy through theheating stabilised by the predetermined amount of electrical energy isthe electrical current or electrical potential or electrical power.

Clause 21. The system of any preceding clause or another embodimentdisclosed herein, wherein the predetermined amount of electrical energyis to stabilise the property of the electrical energy through theheating system (30) to ±25% or ±40% of a nominal value.

Clause 22. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry is to determine theproperty of the flow is during a user inhale through the flow path.

Clause 23. The system of any preceding clause or another embodimentdisclosed herein, the electrical circuitry (8) to determine the propertyrelated to the flow based on a relationship between the property relatedto the flow and the characteristic associated with a second order timederivative of the property of the electrical energy through the heatingsystem (30).

Clause 24. The system of any preceding clause or another embodimentdisclosed herein, wherein the property related to the flow is one ormore of: an amount of one or more components of the aerosol; a start ofan inhale; an end of an inhale; a duration of an inhale.

Clause 25. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) is to maintainconstant a property of the electrical energy to the heating system,wherein said constant property is different to the property of theelectrical energy through the heating system to the determine theproperty related to the flow of the flow path. The constant property maybe one of the current, electrical potential, power.

Clause 26. A method of determining a property of a flow of an aerosolgeneration system (36). The method may include the system or method ofany preceding clause or another embodiment disclosed herein. The methodcomprising: applying a predetermined amount of electrical energy to aheating system (30) to stabilise a property of electrical energy throughthe heating system; determining the property related to the flow basedon the stabilised property of the electrical energy through the heatingsystem.

Clause 27. An aerosol generation system (36) for generation of anaerosol from an aerosol-forming precursor. The system may include thesystem any preceding clause or another embodiment disclosed herein. Thesystem comprising: an electrically operated heating system (30) to heatsaid precursor to generate the aerosol; a flow path (18) fortransmission of flow, including the aerosol, to a user; the heatingsystem arranged in fluid communication with the flow path; electricalcircuitry (8) to determine a property related to the flow of the flowpath based on one of a plurality of different relationships between theelectrical energy through the heating system and said property. Therelationship may include a property of the electrical energy through theheating system, e.g. current, power or and electrical potential.

Clause 28. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry to implement one ofthe plurality of said relationships according to an order of preference.

Clause 29. The system of any preceding clause or another embodimentdisclosed herein, wherein a first relationship comprises an output valueof the property of the flow related to first one or more input valuesdetermined based on the electrical energy through the heating system.

Clause 30. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to determine ifsaid first one or more input values can be obtained based on theelectrical energy through the heating system, and if obtainable todetermine the output value based on the first relationship. Thecircuitry may determine if said values can be obtained in respect of auser inhale through the flow path.

Clause 31. The system of any preceding clause or another embodimentdisclosed herein, wherein the first one or more input values is based onone or more of an: amplitude of an oscillation in the second order timederivative of said electrical energy, e.g. an oscillation due toinitiation and/or termination of an inhalation; an initiation time of auser inhale through the flow path; a duration of a user inhale throughthe flow path; a duration of electrical energy applied to the heatingsystem.

Clause 32. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to determine ifsaid first one or more input values are unobtainable based on theelectrical energy through the heating system, and to determine theoutput value based on another of the plurality of said relationships orthe information according to clause 37.

Clause 33. The system of any preceding clause or another embodimentdisclosed herein, wherein a second relationship comprises the outputvalue related to second one or more input values determined based on theelectrical energy through the heating system, the electrical circuitry(8) to determine if said second one or more input values can be obtainedbased on the electrical energy through the heating system, and ifobtainable to determine the output value based on the secondrelationship.

Clause 34. The system of any preceding clause or another embodimentdisclosed herein, wherein the second one or more input values are asubset of one or more of the first input values.

Clause 35. The system of any preceding clause or another embodimentdisclosed herein, wherein

the second one or more input values is based on a duration of a userinhale through the flow path or a duration of electrical energy appliedto the heating system.

Clause 36. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to determine ifsaid second one or more input values from are unobtainable based on theelectrical energy through the heating system, and to determine theoutput value based on another of the plurality of said relationships orbased on information related to one or more prior user inhales throughthe flow path.

Clause 37. The system of clause 36 or another embodiment disclosedherein, wherein said information is based on an output value determinedfrom a prior user inhale. The information may be based on an outputvalue determined from one or more a prior user inhales, e.g. an average,or other representative quantity of a plurality of inhales. Theinformation may be based on a stored amount, e.g. a default value.

Clause 38. The system of any preceding clause or another embodimentdisclosed herein, wherein the output value is an amount of one or morecomponents of aerosol dispensed during a user inhalation through theflow path.

Clause 39. An aerosol generation system (36) for generation of anaerosol from an aerosol-forming precursor. The system may include thesystem any preceding clause or another embodiment disclosed herein. Thesystem comprising: an electrically operated heating system (30) to heatsaid precursor to generate the aerosol; a flow path (18) fortransmission of flow, including the aerosol, to a user; the heatingsystem arranged in fluid communication with the flow path; electricalcircuitry (8) to determine one of a plurality of classes, the classescomprising one or more input values based on the electrical energythrough the heating system and to determine an output value related to aproperty related to the flow of the flow path based on one of aplurality of different relationships between the electrical energythrough the heating system and said property, wherein the relationshipis selected according to the determined class.

Clause 40. A method of determining a property of a flow of an aerosolgeneration system (36). The method may include the system or method ofany preceding clause or another embodiment disclosed herein. The methodcomprising: determining the output value based on one of a plurality ofdifferent relationships between the electrical energy through theheating system and said output value.

Clause 41. An aerosol generation system (36) for generation of anaerosol from an aerosol-forming precursor. The system may include thesystem any preceding clause or another embodiment disclosed herein. Thesystem comprising: an electrically operated heating system (30) to heatsaid precursor to generate the aerosol; a flow path (18) fortransmission of flow, including the aerosol, to a user; the heatingsystem arranged in fluid communication with the flow path; electricalcircuitry (8) to determine a feature of an oscillation of a property ofelectrical energy through the heating system, the oscillation due toinitiation and/or termination of a user inhale through the flow path,and to determine an amount of one or more components of aerosoldispensed in the inhale based on the feature of the oscillation. Saidfeature may refer to one or more features of said oscillation. Theamount of said one or more component may be the total dispensed for theinhale.

Clause 42. The system of any preceding clause or another embodimentdisclosed herein, wherein the oscillation comprises a maxima and/orminima, which may be adjacent.

Clause 43. The system of any preceding clause or another embodimentdisclosed herein, wherein the feature of the maxima and/or minimaincludes one or more of: an amplitude (including the peak to peak of themaxima and minima); a period; an area bounded by the maxima and/orminima. The amplitude may be a peak to peak amplitude of adjacent maximaand minima.

Clause 44. The system of any preceding clause or another embodimentdisclosed herein, wherein the oscillation is determined from a secondorder time derivative of the property of electrical energy through theheating system.

Clause 44. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) is to determinethe property of the flow during a user inhale through the flow path.

Clause 45. The system of any preceding clause or another embodimentdisclosed herein, wherein the electrical circuitry (8) to determine theoscillation due to initiation and/or termination of a user inhalethrough the flow path by comparison to one or more predeterminedconditions. The circuitry may implement various conditions to search forthe maxima and/or minima, including comparison of one or more of:period; amplitude; position in time with respect to other maxima and/orminima.

Clause 46. An aerosol generation system (36) for generation of anaerosol from an aerosol-forming precursor. The system may include thesystem any preceding clause or another embodiment disclosed herein.

Clause 47. A method of determining a property of a flow of an aerosolgeneration system (36). The method may include the system or method ofany preceding clause or another embodiment disclosed herein. The methodcomprising: determining a feature of an oscillation of a property ofelectrical energy through a heating system, the oscillation due toinitiation and/or termination of a user inhale through the flow path,determining an amount of aerosol dispensed in the inhale based on thefeature of the oscillation.

Clause 48. A computer program when run on programmable electric circuity(6), to execute the method of clause 13 or 26 or 40 or 47, or anypreceding clause or another embodiment disclosed herein.

Clause 49. Electric circuitry (8) for an electrically operated aerosolgeneration system, said circuitry to implement the method of clause 13or 26 or 40 or 47 or any preceding clause or another embodimentdisclosed herein.

Clause 50. A computer readable medium comprising the computer program ofclause 48.

It will be appreciated that any of the disclosed methods (orcorresponding apparatuses, programs, data carriers, etc.) may be carriedout by either a host or client, depending on the specific implementation(i.e. the disclosed methods/apparatuses are a form of communication(s),and as such, may be carried out from either ‘point of view’, i.e. incorresponding to each other fashion). Furthermore, it will be understoodthat the terms “receiving” and “transmitting” encompass “inputting” and“outputting” and are not limited to an RF context of transmitting andreceiving radio waves. Therefore, for example, a chip or other device orcomponent for realizing embodiments could generate data for output toanother chip, device or component, or have as an input data from anotherchip, device or component, and such an output or input could be referredto as “transmit” and “receive” including gerund forms, that is,“transmitting” and “receiving”, as well as such “transmitting” and“receiving” within an RF context.

As used in this specification, any formulation used of the style “atleast one of A, B or C”, and the formulation “at least one of A, B andC” use a disjunctive “or” and a disjunctive “and” such that thoseformulations comprise any and all joint and several permutations of A,B, C, that is, A alone, B alone, C alone, A and B in any order, A and Cin any order, B and C in any order and A, B, C in any order. There maybe more or less than three features used in such formulations.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other elements or steps then those listed in aclaim. Furthermore, the terms “a” or “an,” as used herein, are definedas one or more than one. Also, the use of introductory phrases such as“at least one” and “one or more” in the claims should not be construedto imply that the introduction of another claim element by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim element to inventions containing only one suchelement, even when the same claim includes the introductory phrases “oneor more” or “at least one” and indefinite articles such as “a” or “an.”The same holds true for the use of definite articles. Unless statedotherwise, terms such as “first” and “second” are used to arbitrarilydistinguish between the elements such terms describe. Thus, these termsare not necessarily intended to indicate temporal or otherprioritization of such elements. The mere fact that certain measures arerecited in mutually different claims does not indicate that acombination of these measures cannot be used to advantage.

Unless otherwise explicitly stated as incompatible, or the physics orotherwise of the embodiments, example or claims prevent such acombination, the features of the foregoing embodiments and examples, andof the following claims may be integrated together in any suitablearrangement, especially ones where there is a beneficial effect in doingso. This is not limited to only any specified benefit, and instead mayarise from an “ex post facto” benefit. This is to say that thecombination of features is not limited by the described forms,particularly the form (e.g. numbering) of the example(s), embodiment(s),or dependency of the claim(s). Moreover, this also applies to the phrase“in one embodiment”, “according to an embodiment” and the like, whichare merely a stylistic form of wording and are not to be construed aslimiting the following features to a separate embodiment to all otherinstances of the same or similar wording. This is to say, a reference to‘an’, ‘one’ or ‘some’ embodiment(s) may be a reference to any one ormore, and/or all embodiments, or combination(s) thereof, disclosed.Also, similarly, the reference to “the” embodiment may not be limited tothe immediately preceding embodiment.

As used herein, any machine executable instructions, or compute readablemedia, may carry out a disclosed method, and may therefore be usedsynonymously with the term method, or each other.

The foregoing description of one or more implementations providesillustration and description, but is not intended to be exhaustive or tolimit the scope of the invention to the precise form disclosed.Modifications and variations are possible in light of the aboveteachings or may be acquired from practice of various implementations ofthe present disclosure.

LIST OF REFERENCES

-   36 System    -   2 Apparatus    -   4 Power supply    -   6 Atomizer        -   20 Precursor inlet        -   22 Flow inlet        -   24 Outlet        -   30 Heating system        -   8 Circuitry            -   52 Measurement system            -   58 Shunt resistor            -   60 Amplifier            -   62 Filter        -   54, 64 Processor        -   56 DC:DC converter        -   10 Precursor transmission system            -   14 Storage portion            -   16 Transmission unit    -   12 Delivery system        -   34 Mouthpiece    -   18 Flow path        -   26 Inlet        -   28 Outlet        -   50 flow    -   32 Cartomizer    -   36 Housing    -   34 Mouthpiece-   42 Peripheral device-   94 User interface

1. An aerosol generation system for generation of an aerosol from anaerosol-forming precursor, the system comprising: an electricallyoperated heating system to heat said precursor to generate the aerosol;a flow path for transmission of flow, including the aerosol, to a user,the heating system arranged in fluid communication with the flow path;and electrical circuitry configured to determine a feature of anoscillation associated with a property of electrical energy through theheating system, the oscillation due to initiation and/or termination ofa user inhale through the flow path, and to determine an amount of oneor more components of aerosol dispensed in the inhale based on thefeature of the oscillation.
 2. The system of claim 1, wherein thefeature of the oscillation comprises one or more of: an amplitude, aperiod, and an area of the oscillation.
 3. The system of claim 2,wherein a magnitude of said feature is directly related to an amount ofthe one or more components of aerosol dispensed.
 4. The system of claim1, wherein the oscillation is determined from a second order timederivative of the property of electrical energy through the heatingsystem.
 5. The system of claim 1, wherein the property of the electricalenergy is based on an electrical current through the heating system. 6.The system of claim 1, wherein the electrical circuitry is configured todetermine the oscillation due to initiation and/or termination of a userinhale through the flow path by comparison to one or more predeterminedconditions.
 7. The system of claim 1, wherein the electrical circuitryis configured to apply electrical energy to preheat the heating systemprior to a user inhale through the flow path.
 8. The system of claim 1,wherein the electrical circuitry is configured to generate instructionsfor a user interface to display information based on a determinedproperty of the flow.
 9. The system of claim 1, wherein the electricalcircuitry is configured to determine a property of the flow based on astored relationship between the property of the flow and the feature ofthe oscillation.
 10. The system of claim 1, wherein the electricalcircuitry includes one or more electronic processors communicativelycoupled to a memory.
 11. The system of claim 1, further comprising ahousing arranged to house at least part of the flow path, the heatingsystem and a precursor transmission unit for transmission of precursorto the heating system from a storage.
 12. A method of determining aproperty of a flow of an aerosol generation system for generation of anaerosol from an aerosol-forming precursor, the aerosol generation systemcomprising an electrically operated heating system to heat saidprecursor to generate the aerosol, and a flow path for transmission offlow, including the aerosol, to a user, wherein the heating system isarranged in fluid communication with the flow path, the methodcomprising: determining a feature of an oscillation associated with aproperty of electrical energy through the heating system, theoscillation due to initiation and/or termination of a user inhalethrough the flow path, and determining an amount of aerosol dispensed inthe inhale based on the feature of the oscillation.
 13. A computerprogram comprising instructions which, when executed on programmableelectric circuity, executes the method of claim
 12. 14. Electriccircuitry for an electrically operated aerosol generation system, saidcircuitry configured to implement the method of claim
 12. 15. Anon-transitory computer readable medium comprising the computer programof claim 13.